To date, microglia have shown a role in initiating sexually dimorphic outcomes of NMO relapses compared to MS progression phases, as well as preferential AQP4-ab status, attack localization, and response to treatment however, researchers are uncertain of exactly how microglia are functionally reparative or damaging upon the release of trophic factors in NMO remission [223]. This evidence concerns the gene AQP4 and neuromyelitis optica.